地球学报
地毬學報
지구학보
ACTA GEOSCIENTIA SINICA
2013年
4期
477-484
,共8页
李忠雄%邱海军%程明道%廖建河%王孝勋%王安志%王玲
李忠雄%邱海軍%程明道%廖建河%王孝勛%王安誌%王玲
리충웅%구해군%정명도%료건하%왕효훈%왕안지%왕령
藏北%羌塘盆地%二维地震剖面%构造特征%中央隆起带
藏北%羌塘盆地%二維地震剖麵%構造特徵%中央隆起帶
장북%강당분지%이유지진부면%구조특정%중앙륭기대
northern Tibet%Qiangtang basin%2D seismic profile%structure characteristic%central uplifting belt
针对羌塘盆地复杂的地震地质条件,从提高资料信噪比入手,近几年在羌塘盆地开展了数百千米二维地震采集与处理技术试验,初步总结出一套适合羌塘盆地地震采集与处理方法技术。试验结果证明:单井(18 m以上井深)、16~20 kg炸药药量、50 m以下道距、120次以上覆盖次数、“X”型检波器组合图形为较好的激发接收参数。处理获得的地震叠加剖面反射信息丰富,揭示出盆地古生界基底、三叠系、侏罗系中上部、侏罗系顶界各构造层以及断裂的空间展布特征,为查明地层埋深、构造圈闭和构造界面等提供了高质量数据。另外,穿过中央隆起带的地震剖面清楚显示该隆起带不是一个古老构造,而是一个现今构造。
針對羌塘盆地複雜的地震地質條件,從提高資料信譟比入手,近幾年在羌塘盆地開展瞭數百韆米二維地震採集與處理技術試驗,初步總結齣一套適閤羌塘盆地地震採集與處理方法技術。試驗結果證明:單井(18 m以上井深)、16~20 kg炸藥藥量、50 m以下道距、120次以上覆蓋次數、“X”型檢波器組閤圖形為較好的激髮接收參數。處理穫得的地震疊加剖麵反射信息豐富,揭示齣盆地古生界基底、三疊繫、侏囉繫中上部、侏囉繫頂界各構造層以及斷裂的空間展佈特徵,為查明地層埋深、構造圈閉和構造界麵等提供瞭高質量數據。另外,穿過中央隆起帶的地震剖麵清楚顯示該隆起帶不是一箇古老構造,而是一箇現今構造。
침대강당분지복잡적지진지질조건,종제고자료신조비입수,근궤년재강당분지개전료수백천미이유지진채집여처리기술시험,초보총결출일투괄합강당분지지진채집여처리방법기술。시험결과증명:단정(18 m이상정심)、16~20 kg작약약량、50 m이하도거、120차이상복개차수、“X”형검파기조합도형위교호적격발접수삼수。처리획득적지진첩가부면반사신식봉부,게시출분지고생계기저、삼첩계、주라계중상부、주라계정계각구조층이급단렬적공간전포특정,위사명지층매심、구조권폐화구조계면등제공료고질량수거。령외,천과중앙륭기대적지진부면청초현시해륭기대불시일개고로구조,이시일개현금구조。
It is difficult to acquire high-quality seismic sections in Qiangtang basin because of its complex seismic geological condition and low signal-noise ratio. In order to find out suitable technique for this basin, the authors conducted tests along a seismic profile more than several hundred kilometers long on the basis of increasing signal-noise ratio. The results indicate that a single hole with the depth of at least 18 meters, 16~20 kilogram charge sizes, 20~40 meters trace group interval, more than 120 folds and“X”type geophone array map constitute the optimum shooting and receiving parameters suitable for the feature of Qiangtang basin. And the quality of 2D seismic profiles obtained by using these parameters and techniques can be increased greatly and is obviously superior to that of the profiles obtained in the past. The processed stacking profiles show informative reflection and reveal the features of spatial distribution of Palaeozoic basement, Triassic, middle-upper Jurassic, upper Jurassic strata and faults, thus providing high-quality data for ascertaining the layer thickness and the structural traps and boundaries. In addition, the processed stacking profile across the central uplifting belt clearly shows that this uplifting belt is an anticline structure formed recently instead of an ancient dome.